A deterministic method to calculate the radiation spectra of nuclides

Recently, the computer program IMRDEC has been developed to determine the radiation spectra due to a single atomic-subshell ionisation of a stable atom by a particle, or due to the atomic deexcitation or decay of nuclides. The data needed to describe the deexcitation or decay scheme are obtained from the Evaluated Nuclear Structure Data File (ENSDF) maintained at Brookhaven National Laboratory; this results in the simplest possible input specification. The atomic data as well as the atomic relaxation probabilities are taken from the Evaluated Atomic Data Library (EADL) from Lawrence Livermore National Laboratory. The program IMRDEC calculates the radiation spectra (inclusively the atomic relaxation cascades) deterministically rather than by the Monte Carlo method; this results in much shorter calculational time per nuclide. Since many assumptions still have to be made in determining the atomic relaxation probabilities and in calculating the atomic relaxation, the deterministic method seems to be a small source of inaccuracy.